Telemetric system for angle transmission



Dec. 26, 1939.

E. E. LIBMAN in AL TELEMETRIC SYSTEM FOR ANGLE TRANSMISSION f/To CURRENTSOURCE Filed May 20, 1937 2 Sheets-Sheet 1 TO DIRECT CURRENT SOURCEIrfiventors: Earl E.L.,ibman. Martin A. Edwards. y

. Their Atto rney Dec. 26, 1939. E. E. LIBMAN Er AL 2,184,355

TELEMETRIC SYSTEM FOR ANGLE TRANSMISSION Filed May 20, 1937 2Sheets-Sheet 2 Pi .z. 5?. 2 I

J67 68 flit? "66 I heir/ ttorney;

Patentedv Dec. 26, 1 939 UNITED STATES PATENT OFFICE TELEMETRIC SYSTEMFOR ANGLE TRANSMISSION Earl E. Libman and Martin A. Edwards,Schenectady, N. Y., assignors to General Electric Company, a corporationof New York Application May 20, 1937, Serial No. 143,749 6 Claims. -(c1.177 -337 The stroboscopic system for angle transmission in accordancewith our present invention includes, at the receiving station, astroboscopic device having a motor-driven rotating dial periodicallyilluminated by a discharge of short' duration from a luminous gas tubeor other suitable source of illumination; and at the transmittion, inorder that the dial and the means for ting station, means to determinethe periods of illumination of the dial and to shift the phase ofthe-lamp energization periods with respect to the revolution period orthe dial. There are thus brought together upon the dial two components;one, the flash which illuminates the dial, controlled by the timing ofthe impulse that produces or initiates the' energiz'ing of thestroboscope lamp or tube; and the other, the position of the dial at theinstant the flash is initiated, which is controlled bythe phase of thevoltage applied to the dial driving motor. If the phase of one or bothof these components is progressively changed, an apparent rotation ofthe dial is produced. By suitable arrangements, the phase of eithercomponent may be varied in proportion to the angular displacement ofgiven elements, such as the displacement of a shaft with respect to afixed element. The dial, with suitable calibration, may then be used torepeat the shaft angle.

Further in accordance with the present invenand receiving stations.Instead of being energized from the same current source, however, thedial motor and the means at the transmitting station for determining theperiods of lamp illumination may be separately energized, synchronismbeing maintained by suitable signal means over either wire-or radiochannels.

The current pulse which determines the periodic energization of thestroboscopic lamp or tube is preferably supplied directly over a wirechannel which extends from the transmitter station and is connected to apeaking transformer. However, anyother suitable means for supplying Ithe current pulse over a wire channel from the transmitting stationsynchronously with the rotation of the dial at the receiving station maybe used. Further, the pulse for initiating the periodic energization ofthe stroboscope lamp or tube may be transmitted over a radio channelinstead of over a wire channel.

Preferably the means to determine the lamp energization periods and toshift the phase of these periods with respect to the revolution period aof the dial comprises a phase control device at the transmittingstation, having a fixed winding supplied from the above-mentionedcurrent source and having a rotor adjustable by a suitable manualcontrol means, the device being electrically connected to thestroboscopic .device through means preferably including a peakingtransformer. lamp energization periods may comprise a rotating elementat the transmitting station driven by a motor supplied from the samecurrent source which supplies the dial motor, or the dial motor and themotor for driving the rotating pulse-tim- However, the means. todetermine the l ing element, may be maintained in synchronism by anyother suitable means. When the latter pulse-timing arrangement isemployed, the means to shift the phase of the lamp energization periodsmay comprise a differential gear connection between the synchronousmotor and-the rotatable pulse-timing element driven thereby. Any othersuitable meansfor shifting the phase of the lamp energization periodsmay also be used.

In certain cases the current pulse for energizing thelamps of thestroboscopic devices at a plurality of angle receiving points orstations may be supplied from a single pulse generating means at anangletransmitting point or station; the current pulse to one or more ofsuch plurality of angle receiving stations may then be supplied throughan angle correction device. Further, a

single synchronous motor at an angle transmitting point or station maybe arranged to drive 'a. plurality of pulsegenerating means at difierentspeeds, for operatiomiorexample, of a so-called high and low speed angletransmission system.

Our invention will be better understood from the following descriptionwhen considered'in connection with the accompanying drawings and itsscope will be pointed out in the appended claims.

Referring to the drawings, Fig. 1 is a semidiagrammatic representationof a stroboscopic;

angle-transmission system in which our invenmodification of theembodiment shown in Fig. 1.

In the angle-transmission system illustrated in Fig. 1, R1 indicates anangle receiving station and T1 the corresponding angle transmittingstation. R2 and R3 indicate receiving stations the correspondingtransmitting stations for which, indicated by T2 and T3, are energizedfrom a single generator. The transmitting stations may be separated fromthe receiving stations by any required distance across which the anglesare to be transmitted. Preferably, a single source of low frequencycurrent for the entire system is provided, which may comprise athree-phase generator l0 driven by a motor ll supplied from a suitablesource. The driving current from genera ator III is supplied to thereceiving stations over wire lines l2 and to the transmitting stationsover wire lines [3.

Referring more particularly to the transmitting station T1 and thereceiving station R1 corresponding thereto, at station T1 a phasecontrol device I4 is provided for determining the energization periodsof the stroboscope tube at the receiving station. The phase controldevice I4 is preferably of well known form, comprising, .for example, apolyphase winding (not shown) connected through leads l5 to thethree-phase wire lines l3, and a rotor (not shown) mounted on a shaftIS. The rotor is electrically connected to the primary ll of a peakingtransformer l8. To control the phase of currents transmittedfrom devicel4 a manual control means is provided which may comprise a hand wheel l9connected to shaft l5 through gears 20 and 2|. At the correspondingreceiving station, R1, a synchronous motor 22 is provided, connected tothe threephase lines 12 and arranged to drive an indicating dial 23 of astroboscopic device 24 having an illumination means or lamp 25 connectedto the output circuit 26 of a space discharge device 21.

The latter device is connected to a source of direct current and isprovided with a control electrode 28 in circuit with the secondary 29 ofpeaking transformer l8.

Referring now to the transmitting stations T2 and T3 and thecorresponding receiving stations Rzand R3, for the two transmittingstations a single synchronous motor 30 is provided which is connected tothe three-phase lines l3 and which is arrangedto drive, through a phaseshifting means 3| shown as a-difierential drive gear, a rotating element32 for determining the energization periods of the correspondingstroboscope tubes. present embodiment of the invention as a threephasecurrent generator but other devices comprising rotating elements may beemployed for the purpose. The differential drive gear 3| includes gears33 and 34 connected respectively to the shafts of motor 30 and generator32,'and intermediate gears 35 mounted in a wheel or disk member 36.Member 36 is mounted for rotation about the axis of motor 30 andgenerator 32, means being provided, such as a hand wheel 3! driving apinion 3 8 meshing with teeth 39 in the periphery of wheel 36, to rotatethe wheel 36 by I predetermined amounts corresponding to angles to betransmitted to the receiving stations.

Generator 32 is electrically connected, through lines 40 connected totwo phases of the threephase lines 4|, to the primary 42 of a peakingtransformer 43 similar to peaking transformer l8.

To provide means if desired for correction of ing transformer-l8 whichcontrols the voltage of The rotating element 32 is shown in the theangles transmitted from the generator 32 at station To to one of thereceiving stations, in the present instance R3, the, generator 32 isconnected also, through three-phase lines 4| and 44,

to a phase shifting device 45, which may be located in proximity to theangle transmitting means at station T2, or, as illustrated in Fig. 1,may be located at a separate point, designated'as station Ta. Similarlyto device l4, phase shifting device 45 may comprise a polyphase winding10 (not shown), and a rotor (not shown) mounted on a shaft which isadjustable by means of a hand wheel connected to the shaft throughgearing, therotor being electrically connected to the primary 46 of apeaking transformer 41.

At each of the receiving stations R2 and Re are provided a synchronousmotor, a stroboscopic device having an indicating dial and a lamp, and aspace discharge device having a control electrode, the control electrodebeing connected re- 20 spectively to the secondary 48 of peakingtransformer 43 and to the secondary 49 of peaking transformer-41, allsimilarly to the corresponding parts and connections in receivingstation R1.

In operation of the system illustrated in Fig. 1, 25 referringparticularly to receiving station R1 and transmitting station T1associated therewith, when no angles are being transmitted from T1 toR1, dial 23 is being rotated by motor 22 synchronously with the fieldset up in the polyphase winding of phase control device M by the three;-

' phase current from the commondriving current source [0. During eachrevolution of dial 23 phase control device l4 operates, through peak- 35control electrode 28 of the space discharge device 21, to determine theenergization of lamp 25 for periods of time very brief relative to theperiod of one revolution of the dial 23. The phase relation of the rotorof device l4 with respect to the field set up in the polyphase windingis so set, initially, by adjustment of the rotor shaft l6 by hand wheel[9, that the illumination of disk 23 by the flash from lamp 25 occurs atsuch time in the revolution of dial 23 that the dial appears sta- 45tionary with its scale indicating that the angle transmitted fromstationT1 is zero angle. When it is desired to transmit a given angle,representing for example the angular displacement of a shaftwithreference to its support, the operator 50 at transmitting station T1changes, by means of hand wheel IS, the phase of the rotor of device l4with respect to its field through the given angle, thereby changingcorrespondingly the timing of theenergization of lamp 25 and causing anapparent rotation of the dial 23 which is illuminated by the periodicflashes of the lamp. At the end of the angle-sending operation the dialagain appears stationary with its scale, however, now indicating theangle through which thel transmitting mechanism at station T1 has beenmoved, as above described, by the operator.

Operation of that part of the system shown in Fig. 1 which includes theangle transmitting -means at T2 and T3 and the angle receiving 'means atRe and R3 is similar in certain respects nism by the three-phase currentsupplied by the common source, generator Ill. Generator 32 thendetermines, through peaking transformer 43, the energization periods ofthe dial lamp at R2, and also through phase shitting or angle correctiondevice and peaking transformer 41,

the energizatlon periods oi' the dial lamp at Rs.

The operator at T2 changes, by means of hand wheel '31, the phase ofgenerator 82 with respect to its driving motor 36 through the desiredangle thereby causing the dials of both receiving stations R: and Ra toindicate the angle. Correction or change of the angle sent toone oi thestations, in the present case R3, -may be made by suitable adjustment oithe rotor 0! phase shifting device 45.

In the modification illustrated in Fig. 2, T4 and R4 indicaterespectively an angle transmitting station and an angle receivingstation similar in certain respects to a transmitting station. as T2,and receiving station, as Rs, 0! Fig.- '1. As in Fig. 1, in Fig. 2 asingle source oi current may be provided for driving and synchronizingdistributed to the receiving station R4 over wire .lines 52 and to thetransmitting station T4 over wire lines '53. At the transmitting stationT4 a synchronous motor 54 is provided similar to motor 30 of Fig. 1.However, instead of driving a single generator or other rotatingelement, the motor 54 is arranged to drive a plurality of suchgenerators or rotating elements. For example, two generators, 55 and 56,may be actuated by the single motor 54, both generators being preferablydriven through a single phaseshifting means or differential gear 51identical with differential gear 3| of Fig. 1 and similarly providedwith a hand wheel 58.

The system inwhich the above two generators 55 and 56 are employed maybe a highand low' speed angle transmission system, i. e., a system inwhich desired angles are sent from the transmitting station over twochannels, by means of a high speed generator and a low speed "generator,to corresponding high speed and low speed indicating means at thereceiving station R4. Generator 55, the high speed sending means, isarranged to be driven at the same speed as motor 54, and generator 56,the low speed sending means, is arranged to be driven at a lower speedthan motor 54 through suitable speed reducing means, as gears 59 and 60.At the receivin'g station R4 a plurality of -rotating dial members 6|and 62, corresponding respectively to the rotating elements orgenerators 55and 55 of transmitting, station T4, are provided which maybe driven as shown by separate synchronous motors 53 and 64 suppliedwith current from the comindicating and control apparatus of me muow"the pointer? type. In this apparatus'the' dials or rotating indicatingmembers 6| and 62 are rovided with indicia such as arrows or pointers-H' and I2, and adjacent to and preferably surrounding the dial membersare mounted rotatable ring or other suitably shaped members 15 tionbetween rings II and 14 as between the corresponding generators 55 and56. a suitable driving and speed reducing means, is interposed betweenring 13 and ring 14 which may comprise pinionsll and J6 meshingrespectively with teeth,

on the rims of the rings, and an intermediate gear 16 on the same shaftwith pinion 'll'and meshing with pinion II. The shaft 66 connected .topinion ll may be connected by any suitable means to a given rotatableelement. (not shown) the angular position of which with respect to afixed element is desired to be maintained continually the same as theangle sent to receiving or indicating station R4 from transmitting or directing station T4.

In operation of the modification shown in Fig. 2, generator 55 and dialmembers 6| and 62 are rotated synchronously. at high speed by theirrespective motors 54, 53 and 64, and generator 56 is rotated at areduced'speed determined by the ratio of the speed reducing gears 55and. The operator or director at transmitting station T4 transmits toreceiving station R4 the desired angles by varying by means of handwheel 56 the phase of generators 55 and 56 with respect to their drivingmotor 54, thereby changing correspondingly thetiming ,of theenergization of lamps 65 and 66 and causing an apparent angular movementof the dial pointers II and 12 which are illuminated by the periodicflashes of the lamps. The apparent angular-movement of pointer I2 isreduced with respect to that of pointer II in the ratio of the speedreduction means 59 and connecting high speed genera tor 55 and low speedgenerator 56. In order to follow the angular changes of pointers 1i and12, thus indicated by the-director at transmittingstation T4, shaft.which is connected to the given rotatable element at receiving stationRt whose angular position is' desired to be controlled from transmittingstation T4, is caused to be rotated, by movement of ,the given rotatableelement, as required to maintain the indicia l5 and 16 of ring members13 and I4 inline with the desired angular position of the givenrotatable element at the receiving station R4- is determined by theoperator or director at the transmitting station 'T4.

It will be understood that, as in Fig.- 1, the driving motors in themodification shown inFig. 2

6; and that the current pulse may be transmitted over a radio channelinsteadoi a wirechannel,

Our invention has been described herein in particular embodiments forpurposes 01' illus tration. It is to l e-understood, however, that theinvention is susceptible of various other changes and modifications an'lthat-by the appended claims we intend to cover anysuch modiilcations asfall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent in theUnited States is:

1. In a telemetric system for indicating at a remote point the angularposition of elements at a transmitting point, comprising a source ofalternating current, an indicating dial at said remote point andasynchronous motor connected thereto, an illumination: means for saiddial, means to energize said illumination means for a short periodduring each revolution of said dial including aphase control device atsaid transmitting point, means to connect said source of alternatingcurrent to said synchronous motor and to said phase control device todrive said motor and said device in synchronism, means operativelyassociated with said phase control device to shift the phase of saidperiod with respect to the revolution period of said dial.

2. In a telemetric system for indicating at a remote point the angularposition of elements at a transmitting point, comprising a source ofalternating current, an indicating dial-at said remote point and a lampassociated therewith adapted to illuminate said dial periodically, amotor connected to said dial, means to energize said lamp for apredetermined period during each revolution of said dial including aphase control device at said transmitting point, a peaking transformerconnected between said device and said lamp to shorten the periods ofenergization of said lamp, and means to connect said source ofalternating current to said motor and to said phase control device todrive said motor and said device in synchronism, means operativelyasso-. ciated withsaid phase control device to shift the phase of saidperiod with-respect to the revolution period of said dial.

3. In a telemetric system for indicating at a remote point the angularposition of elements at differential gear interconnecting saidsecondnamed motor and'said rotatable element, and adjustable controlmeans operatively associated with said-gear to change the phase of therevolution period of said elementwith respect to the revolution periodof said second named motor.

4. In a stroboscopic system for indicating at a point remote from atransmitting pointdesired changes in angular position of elements atsaid remote point, in combination, a plurality of dial members at saidremote point, at least one syn-.

chronous motor for driving said dial members, separate illuminationmeans for each of said dial members, a synchronous motor and a pluralityof rotatable elements driven thereby at said transmitting point atpredetermined speeds diiiering in a predetermined ratio, means tooperate said motors in synchronism, means including said ro- .tatableelements to energize the corresponding illumination means for a shortperiod during each revolution of said dial members, means associatedwith said rotatable elements to shift the phase oi said period withrespect to the revolution period of said dial members and to maintainthe degree of phase shift of the periods corresponding to' the severaldial members pointremote from a transmitting point desired changes inangular position of elements at said remote point, in combination, aplurality of dial members at said remote point, at least one synchronousmotor for driving said dial members at the same speed, separateillumination means for each of said dial members, a synchronous motorand a rotatable element driven thereby at said transmitting point, meansto operate said motors in synchronism, means including said rotatableelement-to energize all of said illumination means in synchronism for apredetermined period during each revolution of said dials, meansoperatively associated with said rotatable element to shift the phase ofsaid period with respect to the revolution period of said dials, andmeans including a phase control device operatively associated with atleast one of said illumination means for. shifting independently theenergization period of said one'of said illumination means.

6. In a stroboscopic system for indicating at a point remote irom atransmitting point desired changes in angular position ofian element atsaid remote point, a dial member at said remote point, a synchronousmotor for driving said dial member, an illumination means for said dialmember, a synchronous motor and a current pulse generator driven therebyat said transmitting point, means to operate said motors in synchronism,means to supply a current pulse from said generator for energizing saidillumination means for a short period during each revolution of saiddial, means operatively associated with said generator to shift thephase of said current pulse with respect to the revolution period ofsaid generator driving motor, and means for shiit-= ing thephase ofsaidenergizing period oil-said illumination means with respect to the phaseof said current pulse, said last named phase shift,

means including a phase control device energized 60 MARTIN A. EDWARDS.

